Lucas Oil 10279 Engine Oil Stop Leak - 1 Gallon (Pack of 4)

Well, I bought this because a mechanic put synthetic oil in my friend's 99 Buick LeSabre that had never had synthetic oil. The engine had 175,000 miles on it and never has seen synthetic oil. After running the synthetic oil for about 5,500 miles, a few drops were visible here and there. So, I figured that changing the oil back to organic oil and putting some of this in would fix the problem. I bought this in the winter, but I waited until we got hot weather to use this since I don't know how this will work during -0 degree F starts since it looks very thick. So after changing the oil and filter (using dinosaur oil), I put the whole quart in (I did not overfill). I figured that a 16 year-old engine with 180,000 miles might need to have all the o-rings and seals rehydrated (if that is what you want to call it. The GM 3800 series II stopped dripping the occasional drop after about 1 week. I will take it to the carwash to pressure wash the bottom side of the engine and degrease it, just to see if there is any new oil. But so far, the oil pressure does not seem any different and the oil stopped dripping. So take it from me, putting synthetic oil in an engine that has a lot of miles is not the end of the world. The mechanic put synthetic oil in it because there was the manifold antifreeze leak that could have gotten in the oil. So just in case, he used synthetic once he fixed the antifreeze leak and changed the oil. I do think that the synthetic oil cleaned out some deposits inside the engine. But it only started to leak a few drops, this oil treatment seems to have fixed the problem. I will try and see what happens after the oil is changed again. And, perhaps some can tell me if this would have been OK to use in winter, it sure was thick!

TL;DR Worked for my minor rear main seal leak, but you need to drive the car around for 200-500 miles for the stuff to really be effective. I went to the mechanic with my Range Rover (65k miles, regular maintenance) and discovered there was a fluid leak coming from between the transmission and the motor. They weren't sure if it was oil or transmission fluid. I added UV dye to the oil and determined that it was indeed oil. If this was the case, then the mechanic said that it was highly likely that it was the rear main seal that had failed. I read through all of the online forums and found that oil leaks are common with this model, but several people claimed that they tried Bar's Stop Leak, Lucas Stop Leak, etc. and it stopped the leak. A handful of people had a poor experience. I am most familiar with Lucas products so I chose to give this a try before spending $2000 to drop the transmission to replace the rear main seal. To my surprise, it worked. I drove it around for 50 miles and no sign of leaking. I let the car sit for a few days and there was a huge puddle of oil under the car. Discouraged, I thought it didnt work after all. I cleaned up the oil and took a drive (~200 miles) and all signs of leaking went away again. I've been checking every day and it appears that the leak is gone for now.

does not work like it use to

I can't believe how this worked. I used this in my lawnmower that leaked a small puddle of oil every time I used it. Now not a drop. Best money I've spent in a long time.

At 1 bottle per 6 quarts it slowed my main seal leak. At 2 bottles it really slowed it but at the next oil change it took 30 mins for my thick oil to drain. Results: yes it works, but doesn’t work on large oil leaks. Don’t add more then recommended it will cause hard dry starts and can even break your timing chain if the oil weight is too thick. I used more than recommended so just use the correct amount. Even though I could’ve lived with a little dripping oil I still fixed my main seal but I might still use their other product Lucius engine oil conditioner and stay with 5w30 instead of switching to 10w30 without Lucas because it really made my loud 6.2L high mileage engine quite again. I didn’t even have to shut it off going through drive-though restaurants. Lucas is every bit as good as everyone says!

Good product and fast delivery thank you seller

I have a car with 180k miles on the ODO. The valve cover was leaking but it was not a major problem so I thought this might be a quick fix. To lend some perspective, my leak was not bad enough to leave drops on the floor but one bank of cylinders (it is a V6) clearly showed oil leaking and I could smell it when I parked my garage. I use 5w30 weight Mobil-1 and my car is a 2004 Lexus ES330. I really did not want to remove the valve cover to replace the gasket so I thought this might work especially since there were so many favorable reviews. Be warned, this stuff is like "motor honey." It is very very thick. One bottle went into the crankcase and after 6000 miles I degreased the engine and checked the aluminum head; sadly there was no change and fresh oil is still seeping from the valve cover gasket. Basically, it did nothing for my leak. I worry about the effect of using such a thick compound in the crankcase so I probably won't buy it again. I might work for very small leaks but the lesson here is that there is no quick cheap fix for mechanical wear and tear. Given the high viscosity, I would not recommend it for modern cars that use light weight 0w20 or fuel saving motor oil.

I used this in my Honda with over 325,000 miles, and it’s been a good addition. It helped reduce minor oil seepage and gave me some peace of mind with an older engine. Easy to pour in and didn’t cause any issues. For high-mileage vehicles that are still running strong, this is a solid product to try.

Mix in juiste ratio

واو كان لزوجة جيدة

I've used Lucas Oil products for years and swear by them. I just recently bought a 1997 Dodge Ram 2500 HD with a Cummins diesel and the mechanic I took it to for an inspection told me the engine had multiple leaks (didn't specify their severity). I just did my first oil change and substituted 2 quarts of oil for the Lucas Engine Stop leak and the engine is loving it. I will deep clean the engine and see if there's an improvement with the leaks. In future oil change I will substitute 1 quart of oil for this product as recommended by Lucas.

Works great

I had a very slight oil leak and this product solved the issue after a couple of days of driving. It's not a permanent solution but so far no more leaking. Not sure how this would perform on more serious leaks.